Hundreds of Fabry disease patients sickened because of a U.S. shortage of a drug that keeps them alive are hopeful they soon may get access to a medication previously available only overseas.

The biopharmaceutical company Shire announced that it will fast-track its drug, Replagal, for Food and Drug Administration (FDA) approval so American patients can have access to it.

The drug has been available for the last decade in 46 countries, and about 140 patients with the disease in the United States are receiving Replagal through an investigational clinical trial sanctioned by the FDA.

About 1,200 patients in the U.S. have Fabry disease, a rare genetic disorder that can wreak havoc on the kidneys and cause strokes and early death. The drug replaces a missing enzyme.

Until now, these patients have been taking another drug, Fabrazyme, but, since 2009, its manufacturer, Genzyme, has been unable to keep up production.

Jerry Walter, a semi-retired Army colonel from North Carolina and founder of the
" target="external"> National Fabry Disease Foundation, received the first call from Shire this morning. Because of the Fabrazyme shortage, he has missed two full infusions of the twice-monthly medicine, and is now on only half doses.

"This is great news for Fabry community," said Walter, 56. "It provides treatment options for people with our disease and is a key step in ending the current prolonged drug shortage."

Sylvie Gregoire, president of Shire Human Genetic Therapies, said the new drug might be available to patients within six months. She made the call to Walter this morning.

"We know them personally in the rare-disease business," she said. "Our corporate hat is always off with these patients who motivate and inspire people to work in this business. Patients have been suffering, not knowing exactly when their next doses would come."

The Fabry foundation was one of the key players in getting Shire to apply for FDA approval, writing letters and contacting its the orphan drug development office.

"The news was unexpected and a pleasant surprise," said their lawyer, C. Allen Black of Pittsburgh, who had previously called the shortage, "one of the worst avoidable tragedies in American medicine."

"This story should scare the hell out of everyone in America," Black added. "There's a lot of monopoly out there. It could have hit insulin production or chemotherapy."

With the news today, he told ABCNews.com, "Everybody is really excited about Replagal coming into the market."

Fabry disease is caused by the lack of an enzyme -- alpha-galactosidase-A -- that is required to metabolize lipids or fat-like substances in the body. Its symptoms include chronic gastrointestinal and cardiovascular problems, pains in the hands and feet, renal failure, and skin and eye complications, according to the National Institutes of Neurological Disorders and Stroke.

Fabrazyme utilizes an animal cell and Replagal a human one to replace the human enzyme, but both are considered safe and effective drugs.

Since 2003, the Fabrazyme, which costs about $200,000 a year, has kept Walter and others with the disease alive.

Both Fabrazyme and Replagal are sold overseas.

Genzyme's problems began in June 2009 when the only plant that manufactured the biological drug, in Allston, Mass., was shut down by the FDA because of virus contamination.

Genzyme Shortage of Fabrazyme Hurt Patients

Genzyme admitted to miscalculations in its drug reserves, which caused it to cut back on supplies of Fabrazyme to patients, but it said the shortage would eventually be resolved.

The company was forced to reduce patients to half doses, but in early August Genzyme stopped shipments altogether.

At the time, Bo Piela, vice president of corporate communications at Genzyme, said, "Our highest priority is to restore full supplies of the medicines we make. We are doing everything possible to achieve this and are making good progress toward the approval of a second manufacturing plant that will allow us to significantly increase product supply."

The company is in the midst of constructing a second manufacturing plant in Framingham, Mass., and when that is approved, "we will be able to meet full demands," he said.

"But licensing takes time," he added.

Replagal and Fabrazyme came on the market at the same time, but the FDA gave exclusivity to the Genzyme drug, which has now expired. Shire went on to market its drug in Europe.

"We are coming up on 10 years experience with [Replagal]," said Shire's Gregoire. "We have lots of experience with the product. The reality is the population of Fabry patients in the U.S. has been suffering for two and half years."

Shire offered free treatment to 140 American patients -- about 20 percent of those with the disease -- under a protocol allowed ahead of approval for emergency use.

"We already have a fast-track designation," said Gregoire. "New patients will be able to get it when the product is approved. The standard time is six months, but the agency could do it in a shorter amount of time."

For Walter, whose family has seen 18 members affected by Fabry disease, the news is exciting. He has already exceeded the average age of death for an adult male with the disease, which is 50.

"In the bigger picture, we need treatment options and we can't rely on one medicine and be at risk of a drug shortage happening," said Walter, whose health has been "up and down."

"We have a life-threatening genetic disorder," he said. "The medication works, but it's not a cure."